The growth of managed care has important implications for cancer screening utilization. Previous studies demonstrated that the type of insurance coverage is an important predictor of the use of cancer screening, yet these studies were conducted using data from the early 1990's before the proliferation of new types of managed care plans. It is therefore important to examine recent data on screening utilization that reflects today's health care environment, and to explore what features of health plans and the managed care environment influence screening. This study will examine whether specific characteristics of health insurance plans and the managed care environment influence utilization of breast, cervical, and prostate cancer screening. Rather than only comparing utilization in "managed care" vs. fee-for-service plans, we will analyze specific characteristics across types of plans such as the benefits provided, use of primary care gatekeepers, and the extent of enrollees' provider choice. These characteristics, rather than whether a plan is labeled "managed care", are most likely to influence screening utilization. We will use data from the Medical Expenditure Panel Survey, a nationally representative survey conducted by the Agency for Health Care Policy and Research. The MEPS obtains data not only from individual patients but also from their insurers, which expands and validates individuals' reports of coverage. Furthermore, by linking MEPS data with our own database of environmental characteristics, we will be able to examine whether characteristics of the managed care environment such as HMO market share, competition, and other measures of HMO activity influence utilization. We will also examine patterns of cancer screening utilization in the current managed care context; develop a conceptual framework; examine the relative influence of patient, provider, plan, and environmental factors; and conduct a study of the accuracy of self-reported prostate cancer screening in collaboration with Kaiser Permanente. Examining the factors that influence utilization is important for understanding the impact of the current managed care environment on access, outcomes, and quality of care. The findings will therefore have implications not only for the types of screening examined in this study but also for other health care services.